Incidental multilocular radiolucency of the mandibular ramus

§Chief complaint

Lesion found on a routine radiograph before orthodontic treatment

§Medical & dental history

• 01Fit and well
• 02No family history of jaw cysts or skin cancers
• 03Unerupted 38
• 04No previous extraction or infection in the region

§Clinical examination

• 01Face symmetrical, no visible or palpable expansion
• 02Mild tenderness on deep palpation of the left ramus
• 0338 unerupted; adjacent teeth vital and non-mobile
• 04No paraesthesia of the inferior alveolar nerve

§ figuresFigures (4)

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§Differential diagnosis

§Final diagnosis

Odontogenic keratocyst of the left mandibular ramus

A large lesion causing surprisingly little cortical expansion, growing along the marrow space, is the classic OKC behaviour. Aspiration of thick, cheesy keratin with low soluble protein supports it, and histology confirms a parakeratinised corrugated lining with a palisaded basal layer.

§Investigations

• 01OPG — multilocular radiolucency 45 mm with scalloped corticated margins extending into ramus
• 02CBCT — thinned but intact lingual cortex, no root resorption, IAN canal displaced inferiorly
• 03Aspiration — thick creamy keratinaceous material
• 04Skin and skeletal survey to exclude naevoid basal cell carcinoma syndrome — negative

§Treatment plan

• 01Decompression with a bung for 6 months to reduce lesion volume
• 02Definitive enucleation with peripheral ostectomy and Carnoy's solution
• 03Long-term radiographic surveillance for at least 5 years

§Surgical procedure

• 01Stage 1 — marsupialisation via intraoral window, custom acrylic bung, daily irrigation by patient
• 02Stage 2 at 6 months — enucleation of shrunken lining, removal of 38, peripheral ostectomy with a round bur, modified Carnoy's applied for 3 minutes with nerve protection

§Histopathology report

Cyst lined by uniform 6-8 cell thick parakeratinised stratified squamous epithelium with a corrugated surface and a palisaded, hyperchromatic basal layer. Flat epithelial-connective tissue interface. Daughter cysts present in the wall. No dysplasia. Odontogenic keratocyst.

§Follow-up & outcome

• 01Radiographs at 6, 12, 24, 36 and 60 months
• 02No recurrence at 3 years; nerve function intact throughout

§Clinical pearls / learning points

• 01OKC grows through the medullary space — a huge lesion with a near-normal facial contour should raise suspicion.
• 02Multiple OKCs, especially in a young patient, demand screening for naevoid basal cell carcinoma (Gorlin) syndrome.
• 03Recurrence is highest in the first 5 years; discharge is never appropriate before that.

§Related diseases

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